Extract characters from string starting at the end

Hello all,

I am trying to write a script to update our home-drives in AD to a new location but I need the last part of the string not including the first back-slash, like this:

\\servername\users$\myusername

I would like to store the myusername part in a variable so that I can use it to construct the new home-drive location:

\\newserver\users$\myusername

Please could I have some assistance.

Thanks very much.  This is what I have produced so far:

#Add snap-in and connect to domain

Add-PSSnapin Quest.ActiveRoles.ADManagement | Out-Null

Connect-QADService 'domain.co.uk' | Out-Null

#Get users with home drive we wish to change

$Users = Get-QADUser -SizeLimit 0 -SearchRoot 'DC=domain,DC=co,DC=uk' -SearchScope Subtree | Where {$_.HomeDirectory -like '\\servername*'}

#Go through each user, setting new home drive

ForEach($User in $Users)

{

    $OriginalHomeDrive = $User.homeDirectory

    #Split $OriginalHomeDrive to just username ???

    $SAMAccountName = $User.SAMAccountName

    Set-QADUser -Identity $SAMAccoutName -HomeDrive "M:" -HomeDirectory "\\newserver\users$\$myusername" -proxy -whatif

}